Due to their limited shelf life, the ImmunoTag™ ELISA kits are not typically stocked as finished goods. Please allow 2-3 weeks for delivery. Upon receipt of an order each kit is assembled and tested to ensure that it meets specifications before shipping. Minor changes may occur to the Range, Sensitivity, and Precision and is reflected in the manual supplied with the kit (online manuals are for reference only). In the event of a significant change the order would be confirmed with the customer before shipping.